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It’d be impressive if they fire it at like half the speed of light
I mean, any other non-c speed really.
Actually, c is the speed of light in a vacuum, but light travels slower through a medium, like air. So lasers shot through air will actually travel slower than c.
(For anyone curious, the speed of light in earth air is like 99.97% as fast as in vacuum)
Bunch of nerds in this thread.
You’re in science_memes what did you expected?
hot science girls
Where?
exactly where they should be.
Ya, but that’s JUST slow enough to be able to see it.
Maybe it’s going to be space lasers.
Do you know what the religious affiliation of these space lasers will be?
You have a lot of chutzpah to ask such a question. Oy! What would your mother say?
“You’re so skinny why are you not eating”
Flying Spaghetti Monster
rAmen
A laser strong enough to be used as a weapon will probably not leave a lot of medium on its path.
But the front-most part will still travel at less than c. It will just speed-up after a while.
I’m curious. What happens to the medium? Does it simply get pushed aside? Or pushed along? Or will it eat up some energy and react to something else?
Much like lightning, a powerful enough laser will ionize the air. That ionized air is hot and rises, just like the ionized gasses from combustion.
A powerful laser will look like a beam of fire.
I would be especially interested in speeds larger than c 🙂
Well that’s pretty easy, just fire it anywhere except a vacuum.
But I never use my vacuum. Might as well fire a laser at it!
Yes, ofc - but we’re talking about a weapon here, the air is implied as a medium, and the very-near-c with it.
But a weapon that would construct some sort of structure or a tunnel between it’s position and the target would be something else indeed.
It’s still travelling at c, it’s just bouncing around the medium’s particles on the way. It arrives later because it’s not going in a straight line.
I don’t think that’s a great way of thinking about it. I think you’re describing something more like scattering — or maybe absorption and stimulated or spontaneous emission — which does indeed happen, but is distinct from the index of a medium.
If it were indeed “bouncing,” optics wouldn’t really work, as any n > 1 medium would cause the light to go every which way.
If you fire a laser that goes first through vacuum, then through a lens, then again in vacuum, at what speed is the light travelling on the other side?
It’s same as it was at first. The speed of light depends on the index of refraction of the medium it’s in, but doesn’t depend on its “history.”
I didn’t write it out, but what I was trying to get at was that if it would “slow down”, then it would be slower on the other side. The explanation that the light travels longer through a medium with the same speed would therefore make sense to me.
But then again, how it wouldn’t shoot out in every direction, that doesn’t make sense to me.
I don’t know much about light, that’s why i’m asking. And i’m sure some article or paper would have anwers for that question, I might search it on my own.
Imagine if they made it fire so slow that you could just do a dark souls dodge roll to avoid it
Would you accept 10,000 times slower than the speed of light?
Still too fast to dodge.
Pffft. Amateur.
Yeah, but this requires that the light be travelling through a dense medium to slow down. It still speeds up again when travelling through air or vacuum
Then we could finally have Star Wars laser guns.
just shine a laser through a thing of zircon (n=index of refraction=1.923~2)
so speed of the laser in the zircon = c/n ~c/2
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I have a dollar store laser pointer than can also travel at the speed of light
Pssh, I have a 30 year old flashlight that can do the same.
Wait until you learn how old my sun is
Your sun’s light can travel at the speed of light?
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Claims to travel at the speed of light.
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Still takes eight minutes to get here.
Sus.
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I have a kerosene lantern that does the same.
Dang, that’s rad!
The laser pointer can travel the light of speed? If you turn it on, does the laser not come out of the laser pointer?
The laser and the laser pointer are both traveling away from each other at the speed of light, so from the pointer’s perspective the laser is traveling at twice the speed of light.
You are being downvoted as if your point was offensive or harmful. You are wrong, but it’s totally counter intuitive and I think this is a mistake that everyone makes when studying introductory physics. This would be correct for anything moving at relatively low speeds. But when you’re talking about light, or anything that goes so fast that “percentage of the speed of light” starts being a useful unit to describe their speed, this concept starts being a bit weirder.
This is actually the basic principle of Einstein’s theory of relativity: the speed of light (in a vacuum) is the same for all observers, regardless of their frame of reference. That means that if the laser pointer emits a laser, the light is moving away from the pointer at the speed of light. If the pointer itself is moving at a speed reeeeeally close to the speed of light… Then the laser will STILL be traveling away from the pointer at the speed of light. And if you, an observer in a frame, see the pointer moving at near the speed of light emit a laser… The laser that the laser emitted is also traveling at the speed of light from your point of view.
And there’s no wordplay here. I don’t mean that it’s light, so of course any speed it travels at is the speed of light. I mean that if you measure its speed from any reference frame, you will get around 300000000 m/s, or around 671 million miles per hour. No matter if you are also traveling at near light speed.
Oh wow. TIL.
speed is distance over time, and for light both of those are undefined.
I think you’ve got to be a little careful how you say what you mean here:
In light’s own reference frame, this is true-ish from a pure special relativity perspective. Velocity is sort of undefined in that case because at c, Lorentz transformations bring all distances to zero, meaning that the photon is everywhere at the SAME time. Or said another way, it’s everywhere on its own simultaneity curve. Maybe this is splitting hairs on the definition of “undefined” because, mathematically yeah you’re right, but a rock also moves zero distance in zero time. Its more like it’s velocity doesnt make sense to compute.
From the outside though (as in a non photon frame) this is not true at all. Using laws of refraction you can compute, and even photograph and verify a real, defined speed for a photon in a medium.
That’s impressive. Having a non-photon mass traveling at the speed of light would break our understanding of physics. Get that laser pointer to the lab ASAP
At the speeds it’s moving I imagine we already lost it.
Who allowed them to sell the military equipment??
Wait, how do you make the laser pointer travel at the speed of light? I assume it has some mass.
The army trembling when I bring a mirror
NOW YOU FUCKED UP!
SUPER.
HOT.
World around
Around the world
World around
Around the world
I have wifi router that emits microwaves at the speed of light.
Pffft, I have a microwave that emits microwaves at microwave speeds to microwave things.
This guy microwaves
Impressive. The future is awesome! Can we maybe apply this to regular light too? Maybe even green light? Or purple? I’m so excited.
When you go from green to purple, the light gets more excited too.
insert sensitive chuckle-magazine-guy-meme
sensitive chuckle
Chuckling whilst cold-sore?
Well, for the green light we already have FTL tech, it was invented and perfected by the car behind you as you are waiting for the light to turn green.
Ohhhh right. My bad Sorry…
Is purple actually a light color?
No, but violet is, and that’s pretty close.
According to the Gell-Mann amnesia effect, the same people also write about politics, environment and society.
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I’d be more impressed if they didn’t.
Is there a way to not?
The medium that the laser goes through could slow it down, but it would still be insanely fast.
It would also still be the speed of light. Always is, unless you specify ‘in a vacuum’ every time.
Adding to the fun - The light is still going the same speed within the medium, but it’s bumping into more things. Those collisions divert the light, lengthening the distance it travels through something like 1 cm of glass vs 1 cm in a vacuum. It changes the time it takes to travel through glass rather than the speed at which the light is moving.
At least that’s what I remember from a YouTube video.
Yes that’s it! Thanks for the link!!
The real fun starts when things move faster than the speed of light, that’s when you get Cherenkov radiation!
Sorta, but it’s a pain in the ass.
Just dont.
Wait until they see the speaker that makes noise at the speed of sound.
Honestly I’d be more impressed by the Star Wars kind that go about thirty miles an hour.
Those aren’t lasers. They’re contained plasma projectiles.
Wake me up when I can buy a lightsaber.
Sweet dreams
There was an auction that started at the price of 69420 USD on the 1st of april of 2022
. .
.
.
(The lightsaber is real, selling an extremely dangerous weapon was the joke)
Meanwhile, this headline goes at the speed of clicks:-).
This picture got so much compression artifacts just in 3 days lol.
That’s the lasers working.
Have you not seen those Blaster from the galaxy far far away that fire laser half the speed of sound?
Those are changed plasma bolts
What has science done?!
Has Science Really Gone Too Far Even as Decided to Use Even Go Want to do Look More Like?
Is this a reference to something or just aneurism posting?
It was the OG Aneurism Posting
Aaaah i see. Thanks!
Water is wet
Easy there, that’s quite a can of worms you’re tipping over.
Indeed, many would argue that water can’t be wet, only things that water gets on/in.
